ACI transit routing allows the ACI fabric to pass routing information from one routing "domain" to another. An example of this would be a server connected to one leaf sending and receiving data from a network segment connected to another leaf. The way this works is very similar to MPLS, in that the ACI fabric does not appear as a hop within the routes.
Route peering is where the ACI fabric is used for BGP or OSPF transit between pods.
Many of the steps in configuring this have already been covered in this and previous chapters (detailed in this recipe's How it works...), so instead of reinventing the wheel, let's cover some of the theory and less-discussed specifics.
We have a router connected to Leaf-1 ...